Package de.arstwo.twotil

Class Partition<T>

java.lang.Object

java.util.AbstractCollection<List<T>>

java.util.AbstractList<List<T>>

de.arstwo.twotil.Partition<T>

All Implemented Interfaces:

Iterable<List<T>>, Collection<List<T>>, List<List<T>>, SequencedCollection<List<T>>

public final class Partition<T>
extends AbstractList<List<T>>

Separates a given list into smaller chunks (partitions).

Useful if you want to bulk-process large amounts of data, but want to interrupt for a different task every X items.

Usage example:

   Partition<String> lines = Partition.of(myHugeTextFileData, 500);
   for (List<String> linesChunk : lines) { // gives you a list with up to 500 items
     for (String line : linesChunk) {
       // processing
     }
     updateUI(linesChunk.size());
   }
 
 

Field Summary

Fields inherited from class java.util.AbstractList

modCount

Method Summary

Modifier and Type	Method	Description
List<T>	get(int index)	Returns a chunk of the partitioned content with the given index.
static <T> Partition<T>	of(List<T> list, int chunkSize)	Creates a partitioned view of a given list with a given chunk size.
int	size()

Methods inherited from class java.util.AbstractList

add, add, addAll, clear, equals, hashCode, indexOf, iterator, lastIndexOf, listIterator, listIterator, remove, removeRange, set, subList

Methods inherited from class java.util.AbstractCollection

addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, toArray, toArray, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface java.lang.Iterable

forEach

Methods inherited from interface java.util.List

addAll, addFirst, addLast, contains, containsAll, getFirst, getLast, isEmpty, remove, removeAll, removeFirst, removeLast, replaceAll, retainAll, reversed, sort, spliterator, toArray, toArray

Method Details

of

public static <T> Partition<T> of(List<T> list,
 int chunkSize)

Creates a partitioned view of a given list with a given chunk size.

Type Parameters:

T - any

Parameters:

list - the source data

chunkSize - how many items are in each partition.

Returns:

a partitioned view of the source data.

get

public List<T> get(int index)

Returns a chunk of the partitioned content with the given index.

Specified by:

get in interface List<T>

Specified by:

get in class AbstractList<List<T>>

Parameters:

index - the chunk index of the underlying data.

Returns:

a list of all elements in the requested chunk.

size

public int size()

Specified by:

size in interface Collection<T>

Specified by:

size in interface List<T>

Specified by:

size in class AbstractCollection<List<T>>